The invention relates to a spraying device for spraying liquids, in particular, for spraying liquids for agricultural purposes, having a sprayer-bar arrangement having a liquid supply line running transverse to the direction of travel of a vehicle supporting the spraying device. Sprayer-bar fittings are spaced at intervals for attaching sprayer nozzles, each of which may be independently activated or deactivated by pneumatically or electrically controlled valves. Each of the fittings is configured in the form of a pipe-T having a distributor channel running transverse to the axis of the fittings and facilities on both of its ends for attaching the sprayer nozzles.
A spraying device of this type is known from British patent application GB 2 322 573 A, where three sprayer nozzles equipped with valves arranged in a row and along the direction of travel on a common fitting on the liquid supply line were provided in order to allow varying spraying rates by activating or deactivating one or two sprayer nozzles. This variation is also benefited by the fact that the spraying rates of each of the three sprayer nozzles arranged in a row may also be independently varied for a given supply-line pressure. The sprayer nozzles are configured in the form of oblong sprayer nozzles whose spray fans are inclined at a certain angle with respect to the longitudinal axis of the sprayer bar in order to prevent mutual overlapping of the spray fans of sprayer nozzles aligned along the direction of travel. However, the installation of such permanently attached, screw-on, sprayer nozzles requires relatively large amounts of time and effort due to the large number of sprayer nozzles involved.
An arrangement of sprayer nozzles that may also be employed for agricultural purposes, where each of the sprayer nozzles attached to the liquid supply line at intervals is controlled by a solenoid valve, is known from PCT application WO 98/18560. The sole means for adjusting spraying rate is shutting off individual valves, which gives rise to the problem that localized areas may not be uniformly covered with the medium to be sprayed.
The problem addressed by the present invention is configuring a spraying device of the aforementioned type such that it may be simply installed but, nevertheless, provides even better facilities for making adjustments in order to determine spraying rate.
In order to solve that problem, the invention involves configuring the sprayer nozzles in the form of dual-sprayer-nozzle units having a common distributor bore and a pair of mutually orthogonal coupler sleeves.
This configuration allows arranging dual-sprayer-nozzle units on the respective distributor channel of the fittings such that they can be disposed ahead of, or behind, the liquid supply line, either lined up one behind the other in the direction of travel or arrayed next to one another transverse to the direction of travel, depending upon the choice of coupler sleeve provided on their distributor bore, in a simple manner. Naturally, with this configuration the combination of a dual-sprayer-nozzle valve arranged ahead of the liquid supply line that has its individual sprayer nozzles aligned along the direction of travel and a dual-sprayer-nozzle valve arranged behind the liquid supply line that has its individual sprayer nozzles arrayed transverse to the direction of travel, or vice versa, is also feasible. This sort of configuration thus yields both simple means for making connections and has the advantage that numerous sprayer-nozzle units may be laid out, where, of course, those sprayer nozzles located ahead of, or behind, the liquid supply line may be laid out such that they have differing spraying rates. Since all sprayer nozzles are independently controllable by suitable valves, preferably pneumatically controlled valves, the total spraying rate may be adjusted to suit the particular conditions involved in a simple manner, where the large number of sprayer-nozzle units to be provided yields greater freedom in choosing their layout.
Under a further improvement on the invention, each of the fittings may be provided with a clamping fixture for clamping them onto the liquid supply line. They may then be readily installed in this manner in order that installation of the spraying device will be relatively simple, provided that the fittings on the distributor channel for accommodating the dual-sprayer-nozzle units have been configured in the form of quick-connect fittings in a manner that is well-known.
Under a further improvement on the invention, one of the coupler sleeves provided on the common distributor bore of these dual-sprayer-nozzle units may be centered between the respective axes of the pair of sprayer-valve bodies and the other arranged on a free end of the distributor bore such that the dual-sprayer-nozzle units, along with their sprayer nozzles, may be aligned either parallel to, or transverse to, the direction of travel, as mentioned above, without any special preparations for their installation being required.
Under a further improvement on the invention, it may be provided that the distributor channel of the interconnecting fittings is incorporated into a separate manifold having a central fitting mating to the coupler. This configuration will then allow arranging the interconnecting fittings such that they may be rotated about the coupler, preferably through 90°, in order that the dual-sprayer-nozzle units may be arranged either ahead of and behind the liquid supply line, or beneath the liquid supply line if the distributor channel leading from the coupler to the pair of dual-sprayer valve bodies is routed parallel to, and beneath, the liquid supply line. Of course, in the latter case, due attention will have to be devoted to providing that the valves and dual-sprayer-nozzle units connected to the distributor channel and the swept areas of the latter's rotational motions also lie beneath the liquid supply line, which, however, may be achieved simply by employing a coupler having a suitable length.
Under a further improvement on the invention, the coupler and the fittings mating to the interconnecting fittings are all configured in the form of quick-connect fittings having two latching positions separated by 90°. This configuration allows both simple, rapid, installation and rapidly replacing individual sprayer-nozzle units whenever required.
The valves for controlling the sprayer nozzles may be equipped with spring-loaded, pneumatically actuatable, roller-diaphragm or piston-ring switching devices.
Under a further improvement on the invention, valve plates may be provided with peripheral sealing lips riding on elastic O-ring seals that yield tightly sealed valves and thus prevent undesirable post-spraying drippage from the spraying device in a simple manner. The bodies of the sprayer nozzles may then be installed using union nuts in a well-known manner, where the valve bodies are to be provided with mating threads. An arrangement employing bayonet-lock fittings is also feasible, provided that the components involved have been suitably configured.